Phosph-Akt1 expression is associated with a favourable prognosis in pancreatic cancer

Akt, a serine/threonine protein kinase, mediates growth factor-associated cell survival. In several human cancers, including pancreatic cancer, constitutive activation of Akt (phosphorylated Akt, p-Akt) has been observed and may be associated with chemotherapy and radiotherapy resistance. However, there are contradictory viewpoints in p-Akt in pancreatic cancer on prognosis, and the clinical relevance of p-Akt in pancreatic cancer is not well understood. This study aims to investigate the expressions and relevance of Akt and p-Akt1 in pancreatic cancer tissues and their clinical significance.

The expressions of Akt and p-Akt in 74 surgically resected paraffin-embedded pancreatic ductal adenocarcinoma samples and 10 normal pancreatic tissue samples were examined by immunohistochemistry. The associations of their expression with clinicopathological and survival data were analysed.

The positive expression rate of Akt and p-Akt1 were 87.8% and 83.8%, respectively, which were remarkably higher then those in normal pancreatic tissue (P <0.05). There was a positive correlation between the expression of Akt and p-Akt1. High p-Akt1 expression correlated with lower T stage (P = 0.004), while Akt was not associated with any clinicopathologic variables. Kaplan-Meier survival analysis revealed that higher expression of Akt, p-Akt1 were respectively correlated with favourable prognosis (16.0[4.7-27.3] vs 9.3[9.0-9.6] months, P = 0.007, and 23.0[12.2-33.8] vs 11.1[7.5-14.7] months, P = 0.004, respectively). Multivariate analysis identified p-Akt1 as a significant independent favourable prognostic factor (HR=0.421, P = 0.010).

These results suggest that high p-Akt1 expression may be a favourable prognostic factor in pancreatic cancer.